The bus that powers itself and has no battery? You can buy that on Alibaba. It is made by Nanowinn Technologies of China and it only works in daylight using its state-of-the-art copper indium gallium diselenide solar panels and super-efficient traction motor. Call it a lizard electric vehicle, waking with the sun. It only carries eight people and manages walking speed but, hey, here is the future. It is always laughable first time round. In Uganda, under the cooking sun, there are already large pure electric buses that get a high proportion of their energy from solar panels on the roof. See the IDTechEx Research report, Electric Buses 2016-2026.

A bus that straddles the traffic? Being trialled in China and the next version will carry one thousand people and have so much solar area that 20kW from daylight is in prospect. Time to stop laughing. In 2050, 80% of people will live in cities. Cars will be banned. Indeed, we shall reach peak car around 2030 as one autonomous taxi or bus replaces a large number of private cars, with city managers increasingly discouraging cars by repurposing car parks and imposing swinging congestion charges.

The autonomous bus is interesting. The hardware will be rapidly commoditised but a large software and systems business results as it transmogrifies into something very different. Perhaps there will be combines taxi-buses but do not call them tax-us or the government will get the wrong idea. These may run routes except when they are not needed in this mode when they could be taxis under voice command so even the young and the disabled can go anywhere as needed and keep tapping that wretched phone as social media turns us all into zombies. From China to Canada and New Zealand, young people are losing any interest in car ownership as a status symbol and convenience. See the IDTechEx Research reports, Electric Vehicles Will Change the World 2017-2037 and Autonomous Vehicles Land, Water Air 2017-2037.

Meanwhile, the very structure of the bus is changing with electrics, mechanics and electronics previously made as "components-in-a-box" being replaced by structural electronics - the roof is the solar, the dashboard is the instruments - all as smart materials. See the IDTechEx Research report, Structural Electronics 2017-2027: Applications, Technologies, Forecasts. Hanergy of China has demonstrated energy independent cars it will produce in volume and it uses structural photovoltaics in the outside of the bodywork but also, to power the internal lighting, in the dashboard. The ladder chassis is being replaced with monocoque bodywork increasingly consisting of structural electronics as this two or three functions from one structure frees up space, reduces weight, increases reliability, range and life. What's not to like? In the meantime, Proterra in the USA is using ultra lightweight composite bodywork to increase range and BYD of China saves space by having two near-wheel motors, others planning in-wheel. In-wheel costs more but get you vectored steering, better four wheel drive and so on. Indeed, buses may use the configuration of six in-wheel motors being trialled by start-up Nicola Motors in the USA for giant trucks.

Fuel cell cars seem doomed to being a niche market at best because they have no unique selling proposition, the hydrogen comes from fossil fuels and the charging stations will never be deployed worldwide because the cost would be trillions of dollars with no payback. Fuel cell buses have less of a problem in charging with hydrogen because they run fixed routes and charging can usually be at the depot anyway. Their costs of purchase and ownership are eye watering and their window of opportunity is closing as even double decker and articulated buses are available in battery electric form nowadays and large buses attract 2000 unit orders. Time to stop saying they are not ready for market.

Truth is that buses have a boring image but they are a hotbed of innovation with contactless fast charging coming in and the intermittent overhead catenary charging being trialled with long distance trucks in three countries possibly being relevant to buses so they can be pure electric without the safety, cost and life problems of large batteries. Triboelectric or dielectric elastomer harvesting promises to give kilowatts from bus tires and the trialling energy harvesting suspension definitely will give over 10 kW which can be used to charge the battery to some extent or used to give superb active suspension. Travelling in a bus in pot-holed London or Calcutta will then seem less like standing in a dinghy in a storm at sea. See the IDTechEx Research report, Electric Vehicle Energy Harvesting/ Regeneration 2017-2037.